1. Field of the Invention
The invention relates to a slag transporter, suitable in general for transporting metallurgical transport containers, for picking up and placing slag buckets, for transporting them as well as for emptying the slag from the containers.
In steel-making, large amounts of slag need to be transported and subsequently dumped. For this purpose the slag is filled into a transport container, also termed slag container or slag bucket, generally capable of accommodating roughly 15 to 16 tons of slag. Conventionally the transport distances for the slag container are in the region of roughly 800 m needing to be covered in the steelworks. The slag container is subsequently tilted so that the steel waste can be flow-tipped from the container. In this arrangement it needs to be taken into account that the slag is molten and extremely hot which in conjunction with the very often cramped space availability in the steelworks makes it all the more difficult in handling slag containers.
2. Description of Prior Art
A distinction is made in this field between two basic types. The so-called xe2x80x9cU-frame typexe2x80x9d has the advantage of speedy and facilitated pick-up of the slag buckets and low-level transport thereof, resulting in a low center of gravity of the vehicle and the transporter being highly stable in operation, despite the relatively low deadweight of this type.
As an alternative, so-called xe2x80x9cplatform-typexe2x80x9d slag transporters are put to use when narrower vehicle widths are desired or a high dump capacity is wanted. As compared to the U-frame type vehicle, platform-type vehicles have furthermore the advantage that the tilt angle for the slag bucket is greater in general whereas conventional U-frame type vehicles are restricted to a tilt angle of roughly 130xc2x0 at the most. Because of the restricted tilt angles this often results in the slag not being totally emptied from the bucket where it binds on chilling.
To minimize the disadvantages of the U-frame type vehicles in emptying the slag, i.e. to ensure satisfactory emptying even when restrict ed to a tilt angle of 130xc2x0 beaters are often incorporated in U-frame type slag transporters. These beaters are able to release caked slag from the slag bucket by mechanical agitation such as shaking or jolting.
Described, for example, in DE 44 03 350 A1, is a U-frame type slag transporter characterized by a valve assembly via which the annular surface area of the tilt cylinder is connected to the piston surface area whilst permitting a flow of compressed hydraulic fluid into the piston surface area from the axle cylinders. The valve assembly as described in DE 44 03 350 A1 serves directly in providing a beater means with which releasing hard-caked slag remainders from the slag bucket is made possible hydraulically, i.e. despite the restricted tilt angle the slag remainders can be released by the additional beater means.
However, these additional beater means, a part from the additional design complication they involve which adds to the risk of a malfunction, have further drawbacks. The beating exposes the slag bucket to heavy mechanical loading, resulting in the mounting structure of the slag bucket being highly stressed. This in turn results in relatively fast component fatigue.
The invention is based on the object of proposing a U-frame type slag transporter permitting swivelling of the slag bucket by as much as 180xc2x0.
This object is achieved by a slag transporter including a drive unit, a U-frame type vehicle connected to the drive unit, two rear wheels secured to the rear frame and a tilting means hinged to the vehicle frame for tilting a slag bucket. The tilting means for the slag bucket includes a first tilt frame hinged to the vehicle frame and which is swivable relative to the vehicle frame by a first swivelling means. The tilting means further includes a second tilt frame hinged to the first tilt frame and which is swivable relative to the first tilt frame by a second swivelling means. A mount also forms a part of the tilting means and is provided on the second tilt frame for the bucket trunnions of the slag bucket.
The gist of the invention is to modify the tilting arm of a conventional U-frame type slag transporter such that the tilt angle range from 130xc2x0 to 180xc2x0 is covered by an additional booster. For this purpose a second tilt frame is applied to the tilt frame as existing on conventional type slag transporters, the second tilt frame being swivable relative to the first tilt frame. The mounts for the bucket trunnions of the slag bucket are provided on this second additional tilting arm so that now there is no need to place and regrip the slag bucket when the bucket is swivelled from its transport position into a position by as much as 180xc2x0 relative to the transport position.
It is thus now possible on a U-frame type vehicle too, having no beater means, to pivot a slag bucket through 180xc2x0, i.e. upside-down to thus facilitate releasing the slag from the bucket, especially in releasing it uniformly from the complete bucket.
Thus, in accordance with one preferred embodiment for swivelling the two tilt frames a hydraulic means is provided for each. In usual design of U-frame type slag transporters, swivelling the tilt frame relative to the vehicle frame is likewise assured by hydraulic cylinders. Hydraulic cylinders are relatively simple to control and are rugged. A first hydraulic cylinder for swivelling the first tilt frame is secured for this purpose by its first end to the vehicle frame and by its second end to a middle portion, preferably the main tilt frame. The second hydraulic cylinder serving to swivel the second tilt frame, also termed additional frame, relative to the main tilt frame (first tilt frame) is connected by the its first end in a portion remote from the pivot axis of the first tilt frame and by its second end in a middle portion of the second tilt frame. By actuating the second hydraulic cylinder a pivoting movement of the second tilt frame is achieved relative to the first tilt frame.
The mounts for the bucket trunnions applied to the second tilt frame are provided in a second preferred embodiment with a locking means. The locking means serves to ensure that when the slag bucket is swivelled through 180xc2x0 it is reliably held in the mount in preventing it from sliding out of the mount. When transporting the slag bucket in the transport position too, the locking means additionally safeguards the slag bucket in preventing it from slipping out of place or tilting unwantedly.
Preferably the first tilt frame is U-shaped and comprises overall dimensions so that the first tilt frame can be substantially accommodated within the vehicle frame and/or therebove when the first tilt frame is located relative to the vehicle frame in the transport position. This achieves a low center of gravity of the loaded slag transporter, resulting in the vehicle being stable in operation and thus excelling as regards the safety requirements on the transport vehicle in handling hot slag. The first tilt frame pivoted to each rear open end of the vehicle frame is thus located on the vehicle frame so that the open side of the U-shaped first tilt frame is at the rear in the transporting direction, i.e. that the U formed by the vehicle frame and the U formed by the first tilt frame are each oriented the same.
Advantageously, the second tilt frame is likewise substantially U-shaped. The second tilt frame pivoted to the first tilt frame is likewise oriented so that the open end of the U is located at the rear in the transporting direction when transporting, i.e. that the Us formed by the vehicle frame, the first tilt frame and the second tilt frame are all oriented the same. The second tilt frame is dimensioned to advantage so that it is substantially located on the first tilt frame. At the same time or instead of this arrangement it may also be dimensioned so that it can be accommodated within the first tilt frame to thus avoid any widening of the vehicle.
Preferably the fulcrum of the second tilt frame relative to the first tilt frame is located in the vicinity of the mount for the first swivelling means for the first tilt frame. The second swivelling means is provided in one preferred embodiment at the end remote from the fulcrum of the first tilt frame and applied by its other end to a middle portion of the legs of the U of the second tilt frame. It is this arrangement that ensures that also in the boosted swivelled condition, i.e. when swivelling exceeds approx. 130xc2x0 of the first tilt frame relative to the vehicle frame and swivelling of the second tilt frame of max 50xc2x0 relative to the first tilt frame adequate stability of the vehicle and swivelling means is provided.
Applied to advantage to the vehicle frame are two rockers which in conjunction with each axle cylinder enable the vehicle frame to be lifted and lowered. Lifting and lowering the vehicle frame is of advantage, for one thing, for picking-up the slag bucket from elevated locations or for placement thereon, and, for another, for simplifying dumping depending on the circumstances in the steelworks due to the higher location above ground in the dumping, whereas in transport, the center of gravity remains low to advantage.
In this arrangement the rear wheels of the slag transporter may be configured as single wheels, each applied to a separate rocker. As an alternative to this arrangement it is also possible to configure the rear wheels in a swing or tandem axle arrangement, meaning that two wheels each on one side of the vehicle are connected in series or in parallel, as viewed in the transporting direction by means of a suitable axle connection.